In packing machines of products in mesh bags with handle

ABSTRACT

IMPROVEMENTS IN PACKING MACHINES OF PRODUCTS IN MESH BAGS WITH HANDLE that include: a tubular mesh feeder, a set of rollers in quincunxes, a frame with another set of rollers resting, respectively, on the former, feeders of two bands, plates with springs between both bands, parts shaping folds on the free parts of the mesh, rollers that pull the tubular mesh with its two bands welded and means that close the bottom and cut the top of each bag, feeder rollers of a band and means for transversally cutting it to obtain a strip, turning means that fold the strip in “U”, means for inserting the strip in the upper part of the bag and means for welding this set.

SCOPE OF THE INVENTION

[0001] The purpose of this invention is to improve the packing machines of products in mesh bags with handle. The products to be packed may be fruit, vegetables or others, food products of all classes and, in general, any product or object to be packed forming a bag, normally with a total weight or predetermined amount. Generally, the tubular mesh forming the bag is made of plastic material.

HISTORY

[0002] An automatic machine for shaping and continuous closing of mesh bags obtained from a tubular network is know, which is the purpose of Spanish Invention Patent no. 475.372 granted to Mr. Agustin Dauder Guardiola.

[0003] This machine is basically characterized by the fact it includes a set of two vertical telescopic tubes with the inside fixed and the outside mobile. A third removable tube is placed on the set that carries a certain amount of the tubular mesh. In turn, the set of the three tubes is communicated at the top with the hopper supplying the products to be packed, which have previously been measured in weight and number.

[0004] The mobile tube is activated in the downwards axial direction by an adjustable stroke cylinder, thus performing pulling of the part of mesh envisaged for shaping a bag with suitable capacity for the amount of supplied product, which requires having previously carried out the closure of its base or lower end, returning the mobile tube to its initial position immediately.

[0005] There are means that strangle and collect the mesh part provided, which two sets of blades each and which act on both side of the mesh, moving it in a horizontal transversal plane as regards the axis of the mesh on level with the lower end of the mobile tube in its initial position.

[0006] Said sets of blades are overlapped in their active position, the upper one establishing a support of the bottom of the bag that received the product discharged by the hopper. The blades of the upper set have a narrow part that, in collaboration with the angular edge of the blades of the opposite set, shape the strangling of the mesh. On the bottom of the narrow part there is a cutting and stapling lather head, which is integral with the upper blade set and located on the virtual axis of the telescopic set.

[0007] Operation of the lather head causes the mouth of the already filled bag and the bottom of the next bag to close. Then the blades are separated and a new cycle is started.

[0008] The bags obtained from said machine do not have a handle and each bag is filled with its bottom resting on a stiff support resulting from the set constituted by the upper pair of blades, so that the first parts of the product to be packed hit the stiff support with the mere overlapping of the mesh.

[0009] As regards another known machine, an additional band to print data (type, class, weight and others) of the products contained in the bags and/or to identify their origin must be added. This band is secured only by welding it two ends and the rest is free, that is, bags without handle are obtained from this machine. Furthermore, the structure of the known machine gives rise to a limited performance due to the time it takes to prepare it and the welding.

[0010] Also known is a conventional machine supplied by a plastic material band, specifically a mesh material, that cuts a piece of the band at a certain length based on the size of the bag to be obtained, folds it horizontally in the middle and joins it by heat welding or sewing of the vertical ends of the two opposite walls. Normally, two joined handles are respectively fastened to each of the two walls of the bag so obtained.

[0011] This bag has the disadvantages of increase in the fabrication cost and that it cannot be closed in the case of an eventual and more than probable fall of the products contained therein. Furthermore, it cannot be completely filled as its mouth is not closed and therefore does not guarantee the content of the bag for the buyer.

[0012] According to the above, the upper mouth of this last bag remains open and does not constitute a closed bag with the products inaccessible to the buyers, the access of which implies breaking the upper part by conventional means (for example, scissors).

[0013] On the other hand, the bags open at the top are used by the buyers for filling them with the products they purchase in shopping centers and these bags are bought in specific shops, whilst the closed bags are closed packages once full and, to this effect, sealed, particular of the products to be sold by the shops in question. In other words, that said bags have another application than that of the closed bags and their marketing channels are different.

SUMMARY OF THE INVENTION

[0014] The packing machine of products in mesh bags with handle, provided with the improvements purpose of the invention, is of the type that includes, in a linked way, supply means of a mesh and side bands, means shaping the bags provided with means that close its lower base, means for filling each bag with the corresponding products, means for closing the upper mouth of the full bags and means to transport the full and closed bags towards to the exit of the machine.

[0015] These improvements are characterized by the fact they have a set of at least three loose rollers which are horizontal and located in quincunxes from top to bottom, between which a tubular mesh is moved supplied with interposition of a vertical frame provided, in turn, with at least three other horizontal loose rollers that rest, respectively, on the corresponding rollers of said set where the tubular mesh is inserted; they include two opposite feeders of two thermoplastic material located underneath the loose rollers; they have two vertical opposite plates on the frame driven outwards by elastic means that attach them to the respective zone of the inside surface of the mesh, said zones having the respective bands superimposed against which welding means that perform the heat welding of the two sides of each band are applied to the mesh; they have, underneath the welding means, two vertical and opposite flat wheels that shape two folds towards the inside of the mesh parts free of the bands; they have at least two opposite and horizontal rollers located lower than the flat wheels that turn in opposite directions, applied externally against the set formed by the tubular mesh and the two bands for their transport; and they have heat-welded means that close the bottom of a bag and cut it at the top.

[0016] Likewise, the improvements are characterized by the fact they have, once each bag is filled with the desired products and closed at a certain distance underneath its mouth, feeder rollers of a thermoplastic material band, means for transversally cutting the band in strips, two opposite turning lever means on the same plane that fold the strip in an inverted “U” shape with its free ends folded on each other and other means that insert the folded strip into the upper part of the open mouth of the bag, combined with welds of each part together with the ends of the strip, obtaining the closed bag with the handle.

[0017] The improvements in the packing machines of products in mesh bags with handle, according to the invention, provide amongst others the following advantages as regards what is known:

[0018] a) The bands are not free as each one is fastened to the mesh of each bag by both sides.

[0019] b) There is no mobile tube to push and transport each bag with it being returned in ascent. Instead there is a lower transport of the mesh with the two bands by pulling means with the resulting increase in speed and better performance.

[0020] c) The bags obtained have an initially flat handle made of a strip with folds that unfolds when used.

[0021] d) The final handle, that is attached to the full and closed bag, offers the bag carrier a flat part that opens on being unfolded and conveniently adapts itself to the hand and distributes the stress arising from the weight of the filled bag.

[0022] e) When the bags are filled with the desired products their base does not rest on a stiff support, thus the products received better treatment, especially delicate ones.

[0023] The improvement in packing machines of products in mesh bags with handle, purpose of the invention, provide the advantages described above, apart from others that will be easily inferred from the performance example to be described in detail later on. In order to facilitate understanding of the characteristics mentioned above and at the same time to make known various details, drawings are attached to this description in which a practical performance case is represented as an example and not limitative of the scope of this invention

BRIEF DESCRIPTION OF THE DRAWINGS

[0024]FIG. 1 shows a schematic elevation side view of the zone where the bag is obtained and its lower base or bottom is closed in a packing machine of products in mesh bags provided with the improvements of the invention.

[0025]FIG. 2 corresponds to a schematic front elevation view of said packing machine in the zone where the bag is obtained and its lower base or bottom is closed.

[0026]FIG. 3 is a schematic front elevation view of the packing machine in the zone where the handle is formed and fastened to the mouth of the bag.

[0027]FIG. 4 shows a schematic side elevation view of the packing machine in the zone where the handle is formed and fastened to the mouth of the bag.

PERFORMANCE DESCRIPTION ACCORDING TO THE INVENTION

[0028] It must be taken into account in what follows that the explanation made refers to a static situation of some elements, when in fact and with the packing machine in normal operation, these elements turn or move. However, this is obvious after reading the description that follows.

[0029] In accordance with FIGS. 1 and 2 of the drawings, the station where the mesh bag is obtained and its lower base is closed in a packing machine provided with the improvements of the invention includes the tubular mesh -1- coming from the reel -2- that is moved downwards thanks to a pair of rollers -3- and -4-, one of which at least is motorized.

[0030] The tubular mesh -1- moves around a vertical frame -5- in the way of a template or form, with a very reduced thickness as regards the width. Thus, the tubular mesh adopts an elongated transversal shape with two very close faces. On the lower part and inside the frame -5- there are two opposite vertical plates -6- and -7- that are driven towards the outside by elastic means such as the springs -8- and -9-, which push them against the inside faces of the mesh to be moved downwards.

[0031] The is a variable number of loose rollers on the chassis of the packing machine, such as the three horizontal rollers -10-, -11- and -12- arranged in quincunxes from top to bottom. The frame or form -5-, in turn, has a variable number of loose rollers, such as the three horizontal rollers -13-, -14- and 15- that respectively rest on the three rollers -10-, -11- and 12-. Between these and the rollers of the frame -5- the tubular mesh is moved, following a sinuous path (see FIG. 2).

[0032] At a certain height and lower than the mentioned sinuous path of the mesh, there are two opposite feeders of both bands, such as the reels -16- and -17- that provide both bands -18- and -19- with thermoplastic material, which by means of two rollers -20- and -21- are superimposed on the descending mesh and then welded to it thanks to two welding means -22- and -23-. These, in turn, go in pairs (FIG. 1). The welding means carry out the heat welding of the two sides of each band to the mesh. The bands -18- and -19- may have data relating to the products to be contained in the bags and their origin and may be on one or the two bands.

[0033] Underneath the welding means there are two opposite, vertical and flat wheels -24- and -25- that form two folds -26- and -27- towards the inside (FIG. 1) of the parts of the mesh without the bands.

[0034] Going always from top to bottom, there is then a variable number of pairs of rollers, such as the pair of opposite, horizontal rollers -3- and -4- that turn in opposite directions and are applied externally against the set constituted by the tubular mesh and the two bands, pulling it downwards.

[0035] After than come some welding means, such as the two welds -28- and -29- that close the free bottom of the mentioned set with a heat weld -30-. Underneath this are cutting means, such as the cutters -31- and -32- that cut what will be the end of the upper part of a bag, thus obtaining a bag with its mouth open and with two opposite folds. In FIGS. 1 and 2 the packing machine shows the welds -28- and -29- and the cutting means or cutters -31- and -32- open, that is, in the inactive position, whilst in the description made it is presumed they are in the active position and coordinated, which is what would happen in reality.

[0036] The bags obtained according to the above up to now are transported hanging and with their mouth open, which is expanded by conventional means, passing by a filling station with the desired products. Then each filled bag is closed at a certain distance below its mouth, establishing a free, upper and continuous band. The filled and closed bags are transported to the station where the handle is obtained and its union to the mouth of the corresponding bag.

[0037] In this last station of the packing machine (FIGS. 3 and 4) there are feeder rollers, such as the rollers -33- (this one motorized) and -34- (pressure). This last roller (which has a spring or other means to maintain a certain pressure against the roller -33- with the element to be moved inserted) is not represented in FIG. 4, where only the mechanisms of the handle obtaining stage and a finished bag are sketched. The rollers -33- and -34- supply a thermoplastic material band -35- in the downwards direction coming from a reel -36-.

[0038] When a motorized roller is qualified, this is understood to be operated by a motor, usually electric and, where applicable, through transmission means.

[0039] Next are transversal cutting means -37- of the band -35- in strips -38-. Each strip is transported by a pair of vents -39 a- and -39 b- to a motorized roller -40-. This roller is linked, for example by a chain or cogged belt, to another roller -41- which, in turn, has a plate -42- joined to it that can be moved downwards or upwards. The two vents are placed at the ends of both arms -a- and -b- (FIG. 4).

[0040] Once the vents have been attached by vacuum to the strip -38-, their arms make them turn in the opposite direction according to a 90° angle, shaping the handle -45- in an inverted “U” general shape and with the branches folded as represented in FIG. 4. The vents deposit the two ends of the handle on the roller -40-. At this moment a counter-roller -43- joined to the end of an arm -44-, which may vary according to the arrow of FIG. 3, is applied against the roller -40- with interposition of the ends of the handle. The vacuum of the vents is broken and the arms -a- and -b- turn in the opposite direction to the one before waiting to receive the next strip.

[0041] When the roller -40- is activated, turning according to the arrow of FIG. 3, it pulls the handle -45- downwards, in collaboration with the counter-roller -43-, and at the same time turns the roller -41- causing the plate to descend -42-. The lower end of said plate is applied against the free ends of the handle, resulting in two folds (these are schematically represented in the lower part of the handle -45- of FIG. 3), moving the handle downwards inside the guide -46- until reaching the welders -47- that fasten it to the upper free band of the bag, prior to inserting the two ends of the handle inside the space delimited by the band (see FIG. 3).

[0042] In this way, bags filled with the desired products, closed and provided with a handle for easy carrying are obtained, such as the bag -48- represented in FIG. 3 just before the welders -47- come into operation to fasten the handle and the bag -49- represented in FIG. 4, as the handle is fastened by welding.

[0043] It should be mentioned that, during performance of the improvements purpose of this invention, all the detail variations that experience and practice make advisable as regards shapes and sizes, both absolute and relative, materials used and other circumstances of an accessory nature may be applied, as well as whatever constructive detail modifications considered compatible with the essentiality of what is claimed may be introduced, provided they are considered in the spirit of the following claims. 

1. Improvements in packing machines of products in mesh bags with handle, of the type that includes in a linked way means supplying a mesh and lateral bands, means shaping the bags provided with means to close their lower base, filling means of each bag with the corresponding products, means for closing the upper mouth of the filled bags and means to transport the filled and closed bags towards the machine exit. These improvements are characterized by the fact they have a set of at least three loose rollers which are horizontal and located in quincunxes from top to bottom, between which the supplied tubular mesh moves with interposition of a vertical frame provided, in turn, with at least three other horizontal loose rollers that rest, respectively, on the corresponding rollers of said set where the tubular mesh is inserted. The improvements also include two opposite feeders of two thermoplastic material bands located underneath the loose rollers and have two opposite vertical plates on the frame that are pushed outwards by elastic means that attach them to the respective zone of the inside surface of the mesh, said zones having the respective bands superimposed against which welding means that perform the heat welding of the two sides of each band are applied to the mesh; they have, underneath the welding means, two vertical and opposite flat wheels that shape two folds towards the inside of the mesh parts free of the bands; they have at least two opposite and horizontal rollers located lower than the flat wheels that turn free of the bands; they have at least two opposite and horizontal rollers located lower than the flat wheels that turn in opposite directions, applied externally against the set formed by the tubular mesh and the two bands for their transport; and they have heat-welded means that close the bottom of a bag and cut it at the top.
 2. Improvements in packing machines of products in mesh bags with handle, in accordance with claim 1 , characterized by the fact that once each bag is filled with the desired products and closed at a certain distance underneath the mouth, they include feeder rollers of a thermoplastic material band, means for transversally cutting the band in strips, two opposite turning lever means on the same plane that fold the strip in an inverted “U” shape with its free ends folded on each other and other means that insert the folded strip into the upper part of the open mouth of the bag, combined with welds of each part together with the ends of the strip, obtaining the closed bag with the handle. 